High-pressure press

Abstract

A high-pressure press includes a pressure vessel surrounded by a force-absorbing press frame. The high-pressure press also includes a detection structure for detecting changes in length of at least one column comprised in the press frame, the changes in length depending on the pressure inside the pressure vessel. The detection structure includes a limit switch, which is adapted to detect if the change in length of the column has reached a threshold value and, in that case, interrupt a pressing operation in progress and reduce the pressure inside the pressure vessel.

1. A high-pressure press, comprising:
 a pressure vessel; 
 a force-absorbing press frame surrounding the pressure vessel, and including a column; and 
 a detector for detecting changes in length of the column of the press frame, the changes in length depending on a pressure inside the pressure vessel; 
 wherein said detector includes a limit switch adapted to detect whether the change in length of the column has reached a threshold value corresponding to a pressure inside the pressure vessel, and, if said threshold value has been reached, to interrupt a pressing operation in progress and reduce the pressure inside the pressure vessel. 
 
     
     
       2. The high-pressure press as claimed in  claim 1  wherein said limit switch comprises an arm that is adapted to make contact with one end of said column, the limit switch being affectable by the column affecting the position of the arm in connection with a change in length. 
     
     
       3. The high-pressure press as claimed in  claim 2  wherein the arm is a lever with an end portion adapted to be moved by the column when changing its length in such a manner that the lever pivots on an axis and, thus, with another end portion, performs the interruption of the pressing operation. 
     
     
       4. The high-pressure press as claimed in  claim 1 , further comprising an unloaded member arranged substantially parallel to and adjacent to said column in such a manner that the position of a first portion of the unloaded member is substantially constant relative to the position of a first portion of the column, and in such a manner that the column is allowed to move freely so that the relative position between a second portion of the unloaded member and a second portion of the column is variable, said detector being adapted to detect the change in length of said column in the form of a changed position of said second portion of the column relative to said second portion of the unloaded member. 
     
     
       5. The high-pressure press as claimed in  claim 4  wherein the unloaded member is a rod-shaped member. 
     
     
       6. The high-pressure press as claimed in  claim 5  wherein the rod-shaped member is arranged outside of the press frame and on a side of the press frame facing another direction than the side facing the pressure vessel. 
     
     
       7. The high-pressure press as claimed in  claim 5  wherein the rod-shaped member is arranged in such a manner that a temperature equalization is provided between said column and the rod-shaped member, for both the column and the rod-shaped member to obtain substantially the same temperature. 
     
     
       8. The high-pressure press as claimed in  claim 7  wherein the rod-shaped member, with at least one portion thereof, is adapted to abut against the column for providing said temperature equalization. 
     
     
       9. The high-pressure press as claimed in  claim 5  wherein the rod-shaped member is of substantially the same length as the column, and wherein positions of first and second ends of the rod-shaped member substantially correspond to positions of respective first and second ends of the column. 
     
     
       10. The high-pressure press as claimed in  claim 5  wherein said detector are arranged at one of the second ends of the rod-shaped member and the column. 
     
     
       11. The high-pressure press as claimed in  claim 10  wherein said detector are mounted on said second end of the rod-shaped member in such a manner that the change in length of the column is detected in the form of a changed position of the second end of the column relative to said detector. 
     
     
       12. The high-pressure press as claimed in  claim 1  wherein said detector comprises a measuring device, such as a length sensor, for measuring a continuous change in length of the column. 
     
     
       13. The high-pressure press as claimed in  claim 5  wherein the rod-shaped member is made of a material which has a coefficient of thermal expansion substantially corresponding to the material of said column, at least in a common longitudinal direction. 
     
     
       14. The high-pressure press as claimed in  claim 5  wherein the rod-shaped member has a surface treatment, such as a color treatment, substantially corresponding to that of the column. 
     
     
       15. The high-pressure press as claimed in  claim 5  wherein a surface of the rod-shaped member facing the column is substantially planar. 
     
     
       16. The high-pressure press as claimed in  claim 5  wherein the force-absorbing press frame is wound with wire that induces a compressing prestress acting in the plane of the press frame, and that is arranged on an outer edge surface of the press frame, the rod-shaped member being arranged at a press frame surface without winding. 
     
     
       17. The high-pressure press as claimed in  claim 5 , further comprising a device for measuring the pressure in the press by a corresponding further rod-shaped member and detector, the device and further rod-shaped member and detector being adapted to detect if deformation of the press frame is symmetrical or asymmetrical. 
     
     
       18. The high-pressure press as claimed in  claim 17  wherein said further rod-shaped member is arranged adjacent to a further column comprised in the press frame in such a manner that the rod-shaped and further rod-shaped members are arranged diagonally relative to a symmetry axis of the high-pressure press which is perpendicular to an extension of the columns.